package com.zl.protocol.des;

import com.zl.protocol.MyException;
import org.apache.commons.lang3.ArrayUtils;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.stream.Collectors;

/**
 * @author chenzy
 * @since 2021-11-13
 **/
public class LiDataSecretUtil {
    /*8个二维数组*/
    private static final int[][] S1 =
           {{14, 4,13, 1, 2,15,11, 8, 3,10, 6,12, 5, 9, 0, 7},
            { 0,15, 7, 4,14, 2,13, 1,10, 6,12,11, 9, 5, 3, 8},
            {4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0},
            {15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13}}
     ,S2 = {{15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10},
            {3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5},
            {0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15},
            {13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9}}
     ,S3 = {{10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8},
            {13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1},
            {13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7},
            {1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12}}
     ,S4 = {{7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15},
            {13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9},
            {10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4},
            {3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14}}
     ,S5 = {{2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9},
            {14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6},
            {4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14},
            {11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3}}
     ,S6 = {{12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11},
            {10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8},
            {9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6},
            {4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13}}
     ,S7 = {{4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1},
            {13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6},
            {1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2},
            {6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12}}
     ,S8 = {{13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7},
            {1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2},
            {7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8},
            {2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11}};
    /*一维数组*/
    private static final int[] IP =
            {58, 50, 42, 34, 26, 18, 10, 2, 60, 52,44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48,40
            ,32, 24, 16, 8, 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 61, 53, 45, 37, 29, 21, 13, 5
            ,63, 55, 47, 39, 31,23, 15, 7}
     ,_IP = {40, 8, 48, 16, 56, 24, 64, 32, 39, 7,47, 15, 55, 23, 63, 31, 38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45,13,53
            ,21, 61, 29, 36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11,51, 19, 59, 27, 34, 2, 42, 10, 50, 18, 58, 26,33,1
            ,41, 9, 49,17, 57, 25}
     ,PC1={57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18,10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36, 63, 55,
            47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53,
            45, 37, 29, 21, 13, 5, 28, 20, 12, 4}
     ,PC2={14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10, 23, 19, 12,
            4, 26, 8, 16, 7, 27, 20, 13, 2, 41, 52, 31, 37, 47, 55, 30, 40,
            51, 45, 33, 48, 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32}
            ;
    // 每次密钥循环左移位数
    private static final int[] LS = {1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1};

    /*解密:三重des算法解密,key必须是32位的十六进制数*/
    public static String decryptDES3(String data,String key){
        if (key.length()!=32){
            MyException.errorFillTrace("key必须是32位的十六进制数");
        }
        var key1=key.substring(0,16);
        var key2=key.substring(16,32);

        var dataLength=data.length();
        var remainder=dataLength%16;
        if (remainder!=0){
            /*数据不是16的整数倍时，补A*/
            data+="A".repeat(16-remainder);
            dataLength=data.length();
        }

        var result="";
        for (int i = 0; i < dataLength; i+=16) {
            /*每次只能解析16个字符，8个字节*/
            result+= decryptDES3temp(data.substring(i,i+16),key1,key2);

        }
        return result;
    }
    /*des算法三重解密*/
    private static String decryptDES3temp(String data16,String key1,String key2){
        var temp = discryption(data16, key1);
        temp = DesUtils.encryption(temp, key2);
        return discryption(temp, key1);
    }
    /*对长度为16的数据解密:des算法解密*/
    private static String discryption(String data16,String key1){
        /*把数据转成二进制数，类型为 int数组，每一个int元素为一个bit位*/
        var dataIntArray=hexStr2BitArray(data16);
        /*IP初始置换*/
        dataIntArray=change(dataIntArray,IP);
        /**/
        var left=Arrays.stream(dataIntArray).limit(dataIntArray.length/2).toArray();
        var right=Arrays.stream(dataIntArray).skip(dataIntArray.length/2).toArray();
        var k1=getKeyArray(key1);
        /*下面开始使用旧代码*/
        int[] tmp;
        for (int i = k1.length-1; i >=0 ; i--) {
            var sKey=k1[i];
            tmp = left;
            left = right;
            var fTemp=DesUtils.f(right,sKey);
            right = DesUtils.diffOr(tmp, fTemp);
        }
        // 组合的时候，左右调换**************************************************
        for (int i = 0; i < 32; i++) {
            dataIntArray[i] = right[i];
            dataIntArray[32 + i] = left[i];
        }
        dataIntArray = DesUtils.changeInverseIP(dataIntArray);
        return DesUtils.binaryInt2ASC(dataIntArray);
    }
    /*获取轮子密钥(48bit)*/
    private static int[][] getKeyArray(String key){
        var data=hexStr2BitArray(key);
        data=change(data,PC1);
        var left=Arrays.stream(data).limit(data.length/2).toArray();
        var right=Arrays.stream(data).skip(data.length/2).toArray();

        var reulst= new int[LS.length][PC2.length];
        for (int i = 0; i < LS.length; i++) {
            left=keyLeftMove2(left,LS[LS[i]]);
            right=keyLeftMove2(right,LS[LS[i]]);
            reulst[i]=change(ArrayUtils.addAll(left,right),PC2);
        }
        return reulst;
    }
    /*对data做若干次左移操作，每次左移，把第一位补到最后一位*/
    private static int[] keyLeftMove(int[] data,int moveTimes){
        for (int i = 0; i < moveTimes; i++) {
            int temp0=data[0];
            for (int j = 0; j < data.length-1; j++) {
                data[j]=data[j+1];
            }
            data[data.length-1]=temp0;
        }
        return data;
    }
    /*实现功能与keyLeftMove一样，不过是用list实现的，双循环改为单循环操作*/
    private static int[] keyLeftMove2(int[] data,int moveTimes){
        var list=Arrays.stream(data).boxed().collect(Collectors.toList());
        for (int i = 0; i < moveTimes; i++) {
            list.add(list.remove(0));
        }
        return list.stream().mapToInt(Integer::intValue).toArray();
    }
    /*实现功能与keyLeftMove一样，不过是用list实现的，双循环改为单循环操作*/
    private static Integer[] keyLeftMove3(int[] data,int moveTimes){
        var stream=Arrays.stream(data);
        var iterator=stream.iterator();
        var temp=new ArrayList<Integer>(moveTimes);
        for (int i = 0; i < moveTimes; i++) {
            temp.add(iterator.next());
            iterator.remove();
        }
        var list=stream.boxed().collect(Collectors.toList());
        list.addAll(temp);
        return list.toArray(new Integer[data.length]);
    }
    private static int[] change(int[] data,int[] secret){
        int[] result=new int[secret.length];
        for (int i = 0; i < secret.length; i++) {
            result[i]=data[secret[i]-1];
        }
        return result;
    }
    /*把十六进制的文本转成二进制数，类型为int数组，每一个int元素为一个bit位*/
    private static int[] hexStr2BitArray(String hexStr){
        /*十六进制数的文本很大可能超过long，需要拆成8的倍数*/
        var bitStr="";
        for (int i = 0; i < hexStr.length(); i+=8) {
            bitStr+=hexStr2BitStr8Digist(hexStr.substring(i,i+8));
        }
       return bitStr.chars().map(i -> Integer.valueOf(""+(char)i)).toArray();


    }
    /*8位的十六进制文本转成8*4位的二进制文本*/
    private static String hexStr2BitStr8Digist(String hexStr8Digit){
        var bitStr=Long.toBinaryString(Long.valueOf(hexStr8Digit,16));
        /*toBinaryString得到的二进制文本,第一个1出现之前的0会被舍弃，如果有舍弃，需要补0*/
        return "0".repeat(hexStr8Digit.length()*4-bitStr.length())+bitStr;
    }

    public static void main(String[] args) {
        var data="4D3E0B2817F90960";
        var key ="A79B90CBD17C89F0FFFFFFFF1BB71CEF";
        var result=decryptDES3(data,key);
        System.out.println(result);
    }


}
